It is an exact replica. The number indicates 42 feet, not metres and it is not the Plimsoll Line but the forward draft mark. it tells how far below the water the keel is at the forward end. There are similar marks at the bow.
In the photograph it is giving a false reading...too high. This is because the ship is moving and pushing a "hump" of water ahead of her. You cannot get a true draft unless the ship is stopped in still water... in a dock.
The Plimsoll line is amidship on both sides.

Was the number 42 really the top number on the Titanic's Plimsoll line? Here is a pic from the movie:View attachment 43828
Interesting: the number 42 + dolphins = important subjects in The Hitchhiker's Guide to the Galaxy

I wonder if this is a deliberate reference by James Cameron.

Also, Douglas Adams, who wrote Hitchhiker's Guide, also wrote a book called Starship Titanic about an ill-fated spaceship.

And is that 42 meters or feet?

Click to expand...

I always meant to read Starship Titanic but never got round to it. What would you give it out of 10?